Ring-Opening Copolymerization Using Simple Fe(III) Complexes and Metal- and Halide-Free Organic Catalysts

A comprehensive range of 14 synthetically simple, air-stable, and structurally diverse Fe(III) complexes, comprising salalen, salen, salan, thiolen frameworks, were applied as catalysts to the ring-opening copolymerization (ROCOP) phthalic anhydride (PA) cyclohexene oxide (CHO) without need for extra additives, such co-catalysts, part a newly discovered unary system. Alternating poly(1,2-cyclohexylene-1,2-phthalate) {poly(CHO-co-PA)} was obtained with reasonable molecular weight, narrow dispersity, high % ester linkage. Structure–activity relationships have been investigated discussed. The most interesting discovery that while performing “ligand control” ROCOP experiments (highlighting importance checks in catalysis), all these organocatalysts outperformed their Lewis acidic analogues; results are significant simplistic, metal- halide-free, organocatalytic single-component approach developed. There few examples literature, tending rely on two component systems harsher, air-sensitive chemicals, provide hope more reactive, effective possible an area very much its infancy but will no doubt emerge potentially prove vital future sustainable polymerization research. Thermal properties accessed via differential scanning calorimetry analysis, amorphous copolymers, Tg values ranged by 35 °C from 100 respectable 135 °C.